Chimney cowl



Dec. 14, 1948. J. E. B. WITH CHIMNEY QOWL Filed Jan. 50, 1945 Z2 15. With V IN VEN TOR.

Patented Dec. 14, 1948 VUNlTED STATES PATENT OFFICE CHIMNEY GQWL I Julius E. B. With, Port Townsend, Wash.

Application January 30, 1945, Serial No. 575,270

1 Claim.

This invention relates to chimney cowls and is designed more particularly for use where oil burners are employed for heating or power purposes.

As is well known to those skilled in the art the heat from burners of the type mentioned is not sufiicientto create in. the chimneys or stacks a sufliciently high temperature to insure proper upward displacement of air and gas within the flue. Instead the updraft is dependent upon the fluctuating action of exterior air currents.

An object of the present invention is to provide a chimney cowl which will increase the draft set up in a stack when oil is burned as a fuel and will likewise act to maintain not only a steady draft but also to exclude moisture from the chimney.

With the foregoing and other objects in view which will appear as the description proceeds,

the invention consists of certain novel details 2 of construction and combination of parts hereinafter more fully described and pointed out in the claim, it being understood that changes may be made in the construction and arrangement of parts without departing from the spirit of the invention as claimed.

In the accompanying drawing the preferred form of the invention has been shown.

In said drawings Figure 1 is an elevation of a portion of a chimney equipped with the present improvements.

Figure 2 is an enlarged vertical transverse section through the cowl.

Figure 3 is a section on line 3--3, Fig. 2.

Figure 4 is a section on line 4-4, Fig. 2.

Referring to the figures by characters of reference C' designates a portion of a chimney having the usual or any preferred cap which, in the present instance, is provided with a flue F which is in communication with the interior of the chimney and is preferably of sheet metal with a cylindrical upper end.

The cowl constituting the present invention includes a sleeve I proportioned to fit snugly about the upper end of the flue F. Secured to this sleeve at diametrically opposed points is an arouate plate 2 the width of which is substantially equal to the diameter of the sleeve and the curvature of this plate is such that the portion thereof overlying the sleeve is substantially semicircular, as has been shown at 3. The plate is not shaped at its ends to embrace the sleeve but said end portions, as has been illustrated in Fig. 4, are straight from side to side and are joined to the 2 sleeve 1 at the centers by means of rivets 4 or any other suitable fastening elements.

In addition to the plate 3 there is provided another plate 5 having substantially parallel fiat ends 6 which are riveted or otherwise joined to sleeve I at diametrically opposed points and are positioned at'right angles to the end portions of the plate 2. This is shown in Fig. 4. That portion of the plate between these parallel ends is substantially elliptical, the intermediate portion I of the plate being extended over but spaced from the top portion 3 of the plate 2 while at its opposed sides the top portion 1 merges into the parallel flat portions 6 along substantially semicircular lines as indicated at 8. Thus this plate I has side bulges or rounded portions projecting well beyond the edges of the plate 2 so that side clearances 9 are formed between the side bulges and the plate 2 through which air can flow without passing over the end of the sleeve I.

It has been found in practice that by constructing the cowl as shown a gentle draft will be maintained within the chimney C where oil burners are employed which is not affected by fluctuations of air currents adjacent to the top of the chimney. The two plates act as shields for intercepting strong air currents but at the same time the areas defined above the level of the sleeve l by the respective plates 2 and 5 serve to create a suction which will meet the requirements irrespective of the velocity of the external air. The cowl has the further advantage of shielding the interior of the chimney against the admission of rain or snow or of leaves or other foreign substances of objectionable nature.

It will be noted that when the two plates are properly assembled with the sleeve the ends of the plate 2 will abut against the flat ends 6 of the plate 5 and as these ends of the two plates contact with the sleeve only adjacent to their points of attachment to the sleeve, they are formed upwardly extended short flues I!) which are substantially triangular and open into the area under the curved portion 3 of plate 2. Thus air contained within these triangular flues will be subiected to heat from the sleeve and will gently at right angles to each other, and havingfiat depending ends attached at their centers to the sleeve and abutting against each other to define right angles, said abutting portions of the ends cooperating with the sleeve to define substantially triangular flues extending upwardly between said ends and the sleeve, said flues being open at both ends and both plates overlying said flues, said upper plate having oppositely bulged side portions projectingheyond the' flue at the opposed edges of the lower plate, the top portions of the plates being spaced apart, the width of the lower plate being substantially equal to the diameter of the sleeve and the width of the upper plate being greater than the diameter of the sleeve- JULIUS EJB. WITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

